Have a week's worth of food and safety supplies on hand to avoid having to leave the house. That includes drinking water, canned food, prescription drugs, salt to melt ice on roads and battery-powered lights and radio. Officials in some states, including Minnesota, Michigan and Illinois, are encouraging residents to stay indoors.

If you must go outside, know the right way to wear layers: The layer closest to your skin should be a wool or synthetic material — not cotton. Cotton does a bad job of moisture management. The next layer should be a warm layer that's not cotton, like a sweater or fleece. After that, put on a coat, ideally one that is waterproof and insulated.

3. Watch for signs of frostbite

Depending on the temperature and wind chill, frostbite can set in within minutes. The first sign is a prickly or itchy sensation. Next, the skin will turn red, white, pale or grayish-yellow and start looking hard or waxy. Then comes numbness and blisters. If you get blisters, don't pop them.

4. Leave faucets slightly on

In extremely cold weather, water pipes can freeze and even break. To help prevent this, leave your tap water on a little bit so it's dripping continuously. Also, open your kitchen cabinet doors under the sink to allow more heated air to get to the water pipes.

5. Don't overexert yourself

When shoveling snow or even walking in deep snow, avoid straining too much or the exertion could lead to a heart attack. The American Heart Association recommends not eating a large meal before shoveling, giving yourself frequent breaks, and using a smaller shovel or a snowblower. Warning signs of a heart attack include discomfort in the chest that lasts a few minutes, shortness of breath, and pain or discomfort in the upper body, including the arms, back, neck, jaw or stomach.

6. Protect your pets

For small dogs, shovel a path so they have an area to do their business. Short-haired dogs may need to wear a sweater before going outdoors. Salt spread on walkways can dry out your pet's paws. Give their paws a good wipe-down after they come inside.